The present invention refers in general to arm rests for motor vehicle seats, and is more particularly concerned with an arm rest adapted to be applied to a rear seat having a seating portion and a backrest formed with a central recess in correspondence of which the arm rest is susceptible to be swingably mounted between a raised inoperative position, in which same is received within such a recess and is flush with the backrest surface, and a lowered operative position in which it extends substantially horizontally above the seating portion of the seat.
Known are in the art arm rests for motor vehicle rear seats comprising an elongated body and a load bearing structure incorporated in the body and including swinging mounting means of the arm rest in correspondence of the said recess of the seat backrest, wherein said mounting means comprise a tubular end portion of the load bearing structure which is oriented transverse to the body, and a shaft coaxially inserted through the said tubular end portion and having respective ends protruding from opposite sides of the body for its connection in a stationary condition to the seat backrest so as to allow pivoting of the said tubular end on the said shaft between the raised position and the lowered position of the arm rest.